Clinical History
A 26 year-old woman with history of Kawasaki disease was evaluated for recent episodes of increasing angina. A cardiac CTA, performed four years previously, had demonstrated coronary aneurysms in the distal left main and proximal right coronary artery, for which she has been treated with aspirin and clopidogrel. The recent progression of angina raised concerns about the possibility of distal coronary embolization from the aneurysms, and the introduction of warfarin was considered. A cardiac MRI was ordered to document myocardial scar from prior coronary embolization.
Findings
Cardiac MRI was performed and compared to the previous cardiac CTA done four years before (Figure 1-2). A 3D balanced steady-state free precession (b-SSFP) sequence showed stable size of the two known coronary aneurysms (Figure 3). The left ventricle was mildly dilated with subtle hypokinesis in the mid inferolateral wall (not shown). Left ventricular ejection fraction was preserved at 54%. There was abnormal subendocardial delayed enhancement involving the base and mid anterolateral and inferolateral walls, representing myocardial infarction in the left circumflex territory (Figure 4).
Discussion
Kawasaki disease is a systemic vasculitis presenting in the infant or young child, and is the leading cause of children’s acquired cardiac disease in the United States. About 15-25% of untreated children will develop transient or persistent coronary aneurysms with subsequent risk of ischemic heart disease. Antiplatelet therapy is recommended for coronary aneurysms, and adjunctive anticoagulation with warfarin or low molecular weight heparin should be considered for larger aneurysms. Some patients also develop secondary obstructive coronary artery disease, for which revascularization may be recommended.
Cardiac ultrasound, invasive coronary catheterization, cardiac CTA and cardiac MRI are useful tools to detect, characterize and follow coronary abnormalities. Cardiac MRI represents a versatile non-invasive imaging modality, as it is the gold standard to assess the presence of myocardial scar, and may provide useful information about coronary anatomy.
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